Guo Zezhou, Cui Zehao, Sim Richard, Manthiram Arumugam
Materials Science and Engineering Program & Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA.
Small. 2023 Dec;19(49):e2305055. doi: 10.1002/smll.202305055. Epub 2023 Aug 11.
High-nickel layered oxide cathodes and lithium-metal anode are promising candidates for next-generation battery systems due to their high energy density. Nevertheless, the instability of the electrode-electrolyte interphase is hindering their practical application. Localized high-concentration electrolytes (LHCEs) present a promising solution for achieving uniform lithium deposition and a stable cathode-electrolyte interphase. However, the limited choice of diluents and their high cost are restricting their implementation. Four novel cost-effective diluents and their performance with highly reactive LiNiO cathode and Li-metal anode are reported here. The results show that all the LHCE cells exhibit a Coulombic efficiency of >99.38% in Li | Cu cells and a capacity retention of >85% in Li | LiNiO cells after 250 cycles. Advanced characterizations unveil that the stable cell operation is due to well-tuned electrode-electrolyte interphases and Li deposition morphology. In addition, online electrochemical mass spectroscopy and differential scanning calorimetry reveal that the gas generation and heat-release are greatly reduced with the LHCEs presented. Overall, the study provides new insights into the role of diluents in LHCEs and offers valuable guidance for further optimization of LHCEs for high energy density lithium-metal batteries.
高镍层状氧化物阴极和锂金属阳极因其高能量密度而有望成为下一代电池系统的候选材料。然而，电极-电解质界面的不稳定性阻碍了它们的实际应用。局部高浓度电解质（LHCEs）为实现均匀的锂沉积和稳定的阴极-电解质界面提供了一个有前景的解决方案。然而，稀释剂的选择有限及其高成本限制了它们的应用。本文报道了四种新型经济高效的稀释剂及其与高活性LiNiO阴极和锂金属阳极的性能。结果表明，所有LHCE电池在Li|Cu电池中循环250次后库仑效率>99.38%，在Li|LiNiO电池中容量保持率>85%。先进的表征揭示，电池的稳定运行归因于良好调控的电极-电解质界面和锂沉积形态。此外，在线电化学质谱和差示扫描量热法表明，所呈现的LHCEs大大减少了气体生成和热释放。总体而言，该研究为稀释剂在LHCEs中的作用提供了新的见解，并为进一步优化用于高能量密度锂金属电池的LHCEs提供了有价值的指导。
